WASHINGTON — The Air Force’s top general said today that sexual assaults in his branch of the military typically involve alcohol use and can be traced to a lack of respect for women. “We have a problem with respect for women that leads to many of the situations that result in sexual assault in our Air Force,” Gen. Mark Welsh told reporters in a lengthy interview in his Pentagon offices. He spoke one day after he and other military leaders were summoned to the White House to discuss the sexual assault problem with President Barack Obama, who has expressed impatience with the Pentagon’s failure to solve it. Welsh said combating the problem, which he characterized as a crisis, is his No. 1 priority as the Air Force chief of staff. He said he reviews every reported case of sexual assault; last year there were 792 in the Air Force.